The present invention relates to electrical connection systems for use on vehicles having a pivoting or movable bed. In particular, the invention relates to electrical connect/disconnect system for providing electrical power to electrical components mounted on the movable truck bed.
In a typical hauling vehicle, the hauling bed is movably mounted on the frame of the transport vehicle. For instance, in a dump truck, the dump body is pivotably mounted to the frame of the dump truck. Thus, the dump body can pivot about the rear end of the vehicle to relinquish its load. In other types of hauling vehicles, the hauling body or container is conveyed linearly off the frame, such as by a roller system.
Optimally, a hauling vehicle will include a cover system, which can be employed to cover the open top of the hauling body. An example of one type of widely used cover system is shown in FIG. 1. As shown in this figure, a truck 10 includes a dump bed 11 pivotably mounted on the truck frame 12. A cover or tarp system 14 is mounted to the vehicle and includes a flexible cover or tarpaulin 15 that is attached to one end to a bail arm 17. The bail arm is pivotably mounted to the container bed 11. The opposite end of the tarp 15 is deployed from a tarp roller assembly 16. In a typical system, the bail arm 17 is spring biased to pivot the bail arm toward the rear end of the dump bed 11, thereby drawing the tarp 15 over the open top of the container.
In order to retract the tarp, the tarp roller assembly 16 is rotated in the opposite direction to wind the tarp onto the roller assembly. In some installations, the roller assembly is manually driven by way of a crank arrangement. However, as shown in FIG. 1, an electric motor 18 can be used to drive the roller assembly and retract the tarp 15 into its stored position within the tarp roller assembly 16. An example of a system of this type is the Easy Cover(copyright) tarping system sold by Aero Industries, Inc.
In the case where the tarp system 14 is electrically poweredxe2x80x94i.e., includes an electric motor 18xe2x80x94electricity must be provided to the system. However, since the motor is supported on the dump bed 11, and most preferably on a cab extension 19 of the bed, the motor 18 moves with the dump bed 11. Nominally, when the dump bed 11 is pivoted relative to the vehicle frame 12, the cover system is in its retracted position. Moreover, there is no need to deploy the cover assembly 14 when the dump bed 11 is in its pivoted, unloading, position.
On the other hand, when the dump bed is in its hauling position, such as that shown in FIG. 1, electrical power must be provided to the motor 18 to allow retraction of the tarpaulin 15. Of course, a separate power supply system can be included with the motor 18 or associated with the dump bed 11; however, this is undesirable. As a further alternative, the wiring for connecting the motor 18 to the electrical system of the truck 10 can span the length of the dump bed, pass around the pivot point of the bed and back along the vehicle frame to connect with the vehicle electrical system. Of course, this approach means extending electrical wire along the entire length of the moving dump bed, which is not an optimal solution.
In order to address these problems, wireless disconnect systems have been developed that provide electrical connection when the dump bed is in its hauling position, such as shown in FIG. 1, but that can be disconnected when the bed is moved. One such system utilizes a flat electrical contact plate mounted to the underside of the dump bed at its forward end, and a mating set of electrical contact plates fixed to the vehicle frame in alignment for contact with the plates mounted on the dump bed. This approach frequently does not provide a reliable electrical connection either due to misalignment of the dump bed relative to the frame, or due to wear and corrosion of the contact plates. Consequently, there remains a need for an electrical connect/disconnect system that can reliably provide electrical connection for supplying power to electrical components mounted on a movable dump bed.
In order to address these problems, the present invention contemplates an electrical connection assembly for an electrical component mounted on a bed movably mounted on a frame of a vehicle having a power source. The assembly can comprise a first sub-assembly mountable to the frame and including a first number of electrical contacts electrically connectable to the vehicle power source. Each of the number of electrical contacts can be biased toward the bed of the vehicle when the first sub-assembly is mounted on the frame.
The electrical connection assembly can further comprise a second sub-assembly including a second number of electrical contacts electrically connectable to the electrical component. The second sub-assembly is mountable on the bed of the vehicle so that the second number of electrical contacts move into and out of electrical engagement with the first number of electrical contacts as the bed moves relative to the frame. Each of the second number of electrical contacts can be biased toward the frame of the vehicle, or more particularly toward the first number of electrical contacts, when the second sub-assembly is mounted on the bed.
In one embodiment of the invention, the first sub-assembly can include a first insulator plate mountable to the vehicle frame. The first number of electrical contacts can include at least one electrically conductive plate supported on the first insulator plate. In a specific embodiment, two such plates are supported on the insulator plate. This sub-assembly can include first means for biasing the first insulator plate away from the vehicle frame, in which the first means for biasing is disposed between the first insulator plate and the frame when the first insulator plate is mounted thereto. In one embodiment, this first means for biasing includes a coil spring, which can be concentrically disposed about bolts used to support the plate.
The second sub-assembly can includes a second insulator plate mountable to the bed of the vehicle. The second number of electrical contacts can include a plunger electrically connectable to the electrical component, in which the plunger is movably supported by the second insulator plate. A second means for biasing can be provided for biasing the plunger away from the plate. In one embodiment of the invention, the second insulator plate defines a bore corresponding to the plunger, the plunger being slidably mounted within the bore. Further, the second means for biasing can include a spring disposed within the bore between the plunger and the second insulator plate.
In one feature, the plunger includes an elongated body and an enlarged head disposed within the bore. The second sub-assembly can include a retainer plate disposed over the bore and defining an opening sized to receive the elongated body but not the enlarged head therethrough. The enlarged head of the plunger can define a chamfer adjacent the retainer plate. In one aspect of this embodiment, the opening is sized relative to the elongated body of the plunger to permit the plunger to assume a non-perpendicular angle relative to the retainer plate with the chamfer in contact with the retainer plate. The enlarged head of the plunger can also define a second chamfer adjacent the spring.
In a further aspect of the invention, an electrical connection assembly for an electrical component mounted on a bed movably mounted on a frame of a vehicle having a power source includes a first sub-assembly mountable to the frame and including a first number of electrical contacts electrically connectable to the vehicle power source. A second sub-assembly includes a second number of electrical contacts electrically connectable to the electrical component, the second sub-assembly mountable on the bed of the vehicle so that the second number of electrical contacts move into and out of electrical engagement with the first number of electrical contacts as the bed moves relative to the frame. In one aspect of this embodiment, each of the second number of electrical contacts is biased toward the frame of the vehicle when the second sub-assembly is mounted on the bed. Further, each of the second number of contacts is supported to permit variable angular orientations of the second number of contacts relative to the bed.
The second sub-assembly can includes a second insulator plate mountable to the bed of the vehicle, in which the insulator plate defines a number of bores therein. The second number of electrical contacts can include a plunger electrically connectable to the electrical component, the plunger movably supported within a bore in the insulator plate to permit variable angular orientations of the plunger relative thereto. A means for biasing the plunger away from the plate can be disposed within the bore between the plunger and the plate.
The plunger in this embodiment includes an elongated body and an enlarged head disposed within the bore. A retainer plate is included with the second sub-assembly-that is disposed over the bore and that defines an opening sized to receive the elongated body but not the enlarged head therethrough. The enlarged head of the plunger defines a chamfer adjacent the retainer plate. The opening is sized relative to the elongated body of the plunger to permit the plunger to assume a non-perpendicular angle relative to the retainer plate with the chamfer in contact with the retainer plate.